Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Acute meningitis by Streptococcus suis
Maria-Jesus Corrales-Arroyo,Maria Angeles Del Real-Francia,Amalia Hernandez-Gonzalez,Jose Manuel Morales Puebla
Journal of Microbiology and Infectious Diseases , 2012,
Abstract: Streptococcus suis is a coccus Gram positive, anaerobic optional. Human infection by this microorganism is a zoonoticdisease that usually presents as purulent meningitis. Mortality is low but is common sequelae. A case of meningitis byS. suis secondary to contact with pigs is presented here. A 35-year-old male patient was admitted to the hospital complainingof high fever, malaise, vomiting and headache. A physical examination revealed decreased level of consciousness,with adequate response to painful stimulus and his eyes with deconjugated gaze. S. suis was isolated in bloodculture. He was treated with cefotaxime, vancomycin and acyclovir in the intensive care unit. He experienced progressiveimprovement. He was discharged with severe deafness and a minimally unstable gait as sequellae. J Microbiol Infect Dis2012; 2(4): 160-162Key words: Streptococcus suis, meningitis, deafness.
Meningitis por Streptococcus suis
Geffner Sclarsky,D. E.; Moreno Mu?oz,R.; Campillo Alpera,Ma.S.; Pardo Serrano,F.J.; Gómez Gómez,A.; Martínez-Lozano,Ma.D.;
Anales de Medicina Interna , 2001, DOI: 10.4321/S0212-71992001000600007
Abstract: human infection by streptococcus suis (s. suis) is a zoonosis, with a known occupational risk and clinical presentation mainly as a purulent meningitis with low mortality and frequent hearing loss and ataxia sequela. less than 150 human cases have been reported since original one thirty years ago. there is a geographical distribution most patients living in northen europe and south asia. s. suis disease in human has been reported in two patients in spain the last years. we present two patients with s. suis meningitis, both were men with occupation related by pork meet, and good outcome. they come at our hospital in a lapse of one month. both had neurosensorial hearing loss and walking ataxia. one patient had peripheral facial paralysis and diplopia because of paresia of contralateral sixth nerve, with complete resolution at three months.the rare presentation of s. suis meningitis in our country must not forget us to record the working risk at anamnesis.
Streptococcus suis infection: Clinical manifestations
Dragojlovi? Julijana,Milo?evi? Branko,?a?i? Neda,Pelemi? Miomir
Medicinski Pregled , 2005, DOI: 10.2298/mpns0506236d
Abstract: Introduction Streptococcus suis is a bacterium causing a disease in pigs and rarely in humans. This zoonosis is mostly found as a sporadic disease in individuals that were in contact with the affected or infected pigs: farmers, veterinarians and workers engaged in fresh pork processing. It is assumed that the bacterium enters the body through a cut abrasion in the skin. Initially, the condition resembles a flu, followed by signs of bacteriemia and sepsis. The most frequent clinical manifestation of Streptococcus suis infection is meningitis, leading to hearing loss in over 75% of patients, and subsequent arthritis, endophtalmitis, endocarditis and pneumonia. Toxic shock syndrome with hemorhagic manifestations rarely develops. Material and methods This study included five male patients aged 22 to 63 years treated in the Intensive Care Unit of the Institute of Infectious and Tropical Diseases in Belgrade, due to Streptococcus suis infection. The aim of this study was to point to the existence of this bacteria in our environment, to describe clinical manifestations of the disease and to point out the importance of its prevention. Results All patients had epidemiological evidence of being in contact with pork meat. There were no data about diseased pigs. The estimated incubation period was 4 to 8 days. All patients had meningeal signs. Clinical symptoms included shivering, fever, vomiting, headache, malaise, vertigo and tinitus. Three patients presented with alerterd level of awareness. Four patients developed very severe bilateral hearing impairemnt, whereas one endophtalmtis and one developed endocarditis. The cerebrospinal fluid (CSF) was opalescent in four patients, and only one patient presented with clear CSF. CSF examination showed typical changes characeteristic for bacterial meningitis. Streptoccocus suis was isolated in CSF in all patients, and in one patient the bacteria was isolated in blood as well. All patients underwent treatment with II and III generation cephalosporins and one with one aminoglycosides. All patients were cured, but 4 of them developed sequelae like permanent sensorineural deafness and mild ataxia. Conclusions Streptococcus suis infection is present as a zoonosis in pigs, while humans are contracted occasionally, most frequently related to occupational risk. In cases with bacterial meningitis with sepsis and hearing loss, Streptococcus suis infections must be suspected. Effective prevention requires collaboration between epidemiologists, veterinarians and human medicine physicians. .
Effect of Licochalcone A on Growth and Properties of Streptococcus suis  [PDF]
Huaijie Hao, Wenjia Hui, Peng Liu, Qingyu Lv, Xiaotao Zeng, Hua jiang, Yanzi Wang, Xin Zheng, Yuling Zheng, Jianchun Li, Xuyu Zhou, Yongqiang Jiang
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0067728
Abstract: Streptococcus suis (S.suis) is an important emerging worldwide pig pathogen and zoonotic agent with rapid evolution of virulence and drug resistance. In this study, we wanted to investigate the effect of licochalcone A on growth and properties of Streptococcus suis. The antimicrobial activity of licochalcone A was tested by growth inhibition assay and the minimal inhibitory concentrations (MICs) also were determined. The effect of licochalcone A on S.suis biofilm formation was characterized by crystal violet staining. The effect of licochalcone A on suilysin secretion was evaluated by titration of hemolytic activity. To understand the antimicrobial effect, gene expression profile of S.suis treated by licochalcone A was analyzed by DNA microarray. Our results demonstrated that licochalcone A showed antimicrobial activity on S.suis with MICs of 4 μg/ml for S.suis serotype 2 strains and 8 μg/ml for S.suis serotype 7 strains. Biofilm formation was inhibited by 30–40% in the presence of licochalcone A (3 μg/ml) and suilysin secretion was also significantly inhibited in the presence of licochalcone A (1.5 μg/ml). The gene expression profile of S.suis in the presence of licochalcone A showed that 132 genes were differentially regulated, and we analyzed the regulated genes in the aspect of the bacterial cell cycle control. Among the deregulated genes, the genes responsible for the mass doubling was increased expression, but the genes responsible for DNA replication and cell division were inhibited the expression. So, we think the regulation of the cell cycle genes might provide a mechanistic understanding of licochalcone A mediated antimicrobial effect against S.suis.
Characterization of porcine dendritic cell response to Streptococcus suis
Marie-Pier Lecours, Mariela Segura, Claude Lachance, Tufaria Mussa, Charles Surprenant, Maria Montoya, Marcelo Gottschalk
Veterinary Research , 2011, DOI: 10.1186/1297-9716-42-72
Abstract: Streptococcus suis is a major swine pathogen associated mainly with meningitis, although other pathologies have also been described such as septicemia with sudden death, endocarditis, arthritis, and pneumonia [1]. Among 35 serotypes described, serotype 2 is considered the most virulent and the most frequently isolated from both diseased pigs and humans. Consequently, most studies on virulence factors and the pathogenesis of infection have been carried out with this serotype [2]. Until recently, S. suis disease in humans has been considered as rare and only affecting people working with pigs or pork by-products. However, with a rising incidence in humans over the last years, S. suis is now considered as an important emerging zoonotic agent, especially in Asian countries, where S. suis has recently been identified as the leading cause of adult meningitis in Vietnam, the second in Thailand, and the third in Hong Kong. In 2005, an important outbreak occurred in China and resulted in 200 human cases with a fatality rate near 20% [1]. In humans, S. suis is mainly responsible for meningitis, septicemia and streptococcal toxic shock-like syndrome [1,3,4].Despite the increasing number of studies, the pathogenesis of the S. suis infection is still not completely understood and, to date, attempts to control the infection are hampered by the lack of an effective vaccine. The mechanisms involved in the host innate and adaptive immune responses toward S. suis as well as those used by S. suis to subvert these responses are unknown. Several virulence factors have been proposed to be involved in the pathogenesis of S. suis infection [5]. Among them, the capsular polysaccharide, which confers to the bacteria antiphagocytic properties, has been demonstrated as a critical virulence factor [2,6,7] and its structure was recently described [8]. In fact, non-encapsulated mutants were shown to be avirulent in mice and pig models of infection [2]. Among several proteins and enzymes, a hemoly
Swine infection by Streptococcus suis: a retrospective study
Del'Arco, A.E.;Santos, J.L.;Bevilacqua, P.D.;Faria, J.E.;Guimar?es, W.V.;
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2008, DOI: 10.1590/S0102-09352008000400016
Abstract: the epidemic aspects of swine infections caused by streptococcus suis were studied, focusing mainly on the occurrence of several serotypes. a total of 323 samples of s. suis were isolated from clinically ill animals, serotyped according to the co-agglutination procedure, and analyzed. the serotyping revealed that s. suis was present in several brazilian states. the largest number was isolated from the states of minas gerais (62.5%), s?o paulo (10.8%), and paraná (9.3%). serotype 2 was the most frequent (61.0%), followed by the serotypes 1, 3, 4, 7, and 8. the largest number of isolations was obtained from the brain (60.1%), followed by the lungs (10.4%). about 9.4% of the cases were due to septicemia.
Lysozyme Resistance in Streptococcus suis Is Highly Variable and Multifactorial  [PDF]
Paul J. Wichgers Schreur, Christian van Weeghel, Johanna M. J. Rebel, Mari A. Smits, Jos P. M. van Putten, Hilde E. Smith
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0036281
Abstract: Background Streptococcus suis is an important infectious agent for pigs and occasionally for humans. The host innate immune system plays a key role in preventing and eliminating S. suis infections. One important constituent of the innate immune system is the protein lysozyme, which is present in a variety of body fluids and immune cells. Lysozyme acts as a peptidoglycan degrading enzyme causing bacterial lysis. Several pathogens have developed mechanisms to evade lysozyme-mediated killing. In the present study we compared the lysozyme sensitivity of various S. suis isolates and investigated the molecular basis of lysozyme resistance for this pathogen. Results The lysozyme minimal inhibitory concentrations of a wide panel of S. suis isolates varied between 0.3 to 10 mg/ml. By inactivating the oatA gene in a serotype 2 and a serotype 9 strain, we showed that OatA-mediated peptidoglycan modification partly contributes to lysozyme resistance. Furthermore, inactivation of the murMN operon provided evidence that additional peptidoglycan crosslinking is not involved in lysozyme resistance in S. suis. Besides a targeted approach, we also used an unbiased approach for identifying factors involved in lysozyme resistance. Based on whole genome comparisons of a lysozyme sensitive strain and selected lysozyme resistant derivatives, we detected several single nucleotide polymorphisms (SNPs) that were correlated with the lysozyme resistance trait. Two SNPs caused defects in protein expression of an autolysin and a capsule sugar transferase. Analysis of specific isogenic mutants, confirmed the involvement of autolysin activity and capsule structures in lysozyme resistance of S. suis. Conclusions This study shows that lysozyme resistance levels are highly variable among S. suis isolates and serotypes. Furthermore, the results show that lysozyme resistance in S. suis can involve different mechanisms including OatA-mediated peptidolycan modification, autolysin activity and capsule production.
Streptococcus suis, an Important Cause of Adult Bacterial Meningitis in Northern Vietnam  [PDF]
Heiman F. L. Wertheim, Huyen Nguyen Nguyen, Walter Taylor, Trinh Thi Minh Lien, Hoa Thi Ngo, Thai Quoc Nguyen, Bich Ngoc Thi Nguyen, Ha Hong Nguyen, Ha Minh Nguyen, Cap Trung Nguyen, Trinh Tuyet Dao, Trung Vu Nguyen, Annette Fox, Jeremy Farrar, Constance Schultsz, Hien Duc Nguyen, Kinh Van Nguyen, Peter Horby
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0005973
Abstract: Background Streptococcus suis can cause severe systemic infection in adults exposed to infected pigs or after consumption of undercooked pig products. S. suis is often misdiagnosed, due to lack of awareness and improper testing. Here we report the first fifty cases diagnosed with S. suis infection in northern Viet Nam. Methodology/Principal Findings In 2007, diagnostics for S. suis were set up at a national hospital in Hanoi. That year there were 43 S. suis positive cerebrospinal fluid samples, of which S. suis could be cultured in 32 cases and 11 cases were only positive by PCR. Seven patients were blood culture positive for S. suis but CSF culture and PCR negative; making a total of 50 patients with laboratory confirmed S. suis infection in 2007. The number of S. suis cases peaked during the warmer months. Conclusions/Significance S. suis was commonly diagnosed as a cause of bacterial meningitis in adults in northern Viet Nam. In countries where there is intense and widespread exposure of humans to pigs, S. suis can be an important human pathogen.
Carbohydrate Availability Regulates Virulence Gene Expression in Streptococcus suis  [PDF]
M. Laura Ferrando, Peter van Baarlen, Germano Orrù, Rosaria Piga, Roger S. Bongers, Michiel Wels, Astrid De Greeff, Hilde E. Smith, Jerry M. Wells
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0089334
Abstract: Streptococcus suis is a major bacterial pathogen of young pigs causing worldwide economic problems for the pig industry. S. suis is also an emerging pathogen of humans. Colonization of porcine oropharynx by S. suis is considered to be a high risk factor for invasive disease. In the oropharyngeal cavity, where glucose is rapidly absorbed but dietary α-glucans persist, there is a profound effect of carbohydrate availability on the expression of virulence genes. Nineteen predicted or confirmed S. suis virulence genes that promote adhesion to and invasion of epithelial cells were expressed at higher levels when S. suis was supplied with the α-glucan starch/pullulan compared to glucose as the single carbon source. Additionally the production of suilysin, a toxin that damages epithelial cells, was increased more than ten-fold when glucose levels were low and S. suis was growing on pullulan. Based on biochemical, bioinformatics and in vitro and in vivo gene expression studies, we developed a biological model that postulates the effect of carbon catabolite repression on expression of virulence genes in the mucosa, organs and blood. This research increases our understanding of S. suis virulence mechanisms and has important implications for the design of future control strategies including the development of anti-infective strategies by modulating animal feed composition.
Streptococcus suis, an Emerging Drug-Resistant Animal and Human Pathogen  [PDF]
Bruna Facinelli
Frontiers in Microbiology , 2011, DOI: 10.3389/fmicb.2011.00235
Abstract: Streptococcus suis, a major porcine pathogen, has been receiving growing attention not only for its role in severe and increasingly reported infections in humans, but also for its involvement in drug resistance. Recent studies and the analysis of sequenced genomes have been providing important insights into the S. suis resistome, and have resulted in the identification of resistance determinants for tetracyclines, macrolides, aminoglycosides, chloramphenicol, antifolate drugs, streptothricin, and cadmium salts. Resistance gene-carrying genetic elements described so far include integrative and conjugative elements, transposons, genomic islands, phages, and chimeric elements. Some of these elements are similar to those reported in major streptococcal pathogens such as Streptococcus pyogenes, Streptococcus pneumoniae, and Streptococcus agalactiae and share the same chromosomal insertion sites. The available information strongly suggests that S. suis is an important antibiotic resistance reservoir that can contribute to the spread of resistance genes to the above-mentioned streptococci. S. suis is thus a paradigmatic example of possible intersections between animal and human resistomes.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.